Omega-3 fatty acids have been shown to be associated with health throughout life. For example, studies have shown that EPA and DHA are important for normal fetal development, including neuronal, retinal, and immune function. EPA and DHA may affect many aspects of cardiovascular function, including inflammation, peripheral artery disease, major coronary events, and anticoagulation.

Omega-3 fatty acids are essential fatty acids (EFAs), which the body cannot synthesize in sufficient quantities and are therefore an important part of our diet. Omega-3 are polyunsaturated fatty acids (PUFAs) because they are made up of two or more double bonds. Omega-3 fatty acids include alpha-linolenic acid (ALA), which is found in canola and margarine, flaxseed oil, certain nuts (such as walnuts) and legumes, and in small amounts in leafy vegetables. Omega-3 fatty acids also include a group of long-chain (LC) fatty acids, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and docosapentaenoic acid (DPA). They are mainly found in oily fish, such as mackerel, herring, sardines, salmon, tuna, trout, marine fish, and snapper, as well as other seafood. Therefore, omega-3 supplements used in the food industry are mainly obtained from fish (as shown in the figure below).

Behl, T., & Kotwani, A. (2017). Omega-3 fatty acids in prevention of diabetic retinopathy. Journal of Pharmacy and Pharmacology, 69(8), 946-954. [Link]
Intakes, I. R. D. (2005). Nutrient Reference Values for Australia and New Zealand. Commonwealth Department of Health and Ageing: Australia. [Link]
Rubio-Rodríguez, N., Beltrán, S., Jaime, I., Sara, M., Sanz, M. T., & Carballido, J. R. (2010). Production of omega-3 polyunsaturated fatty acid concentrates: A review. Innovative Food Science & Emerging Technologies, 11(1), 1-12. [Link]
Swanson, D., Block, R., & Mousa, S. A. (2012). Omega-3 fatty acids EPA and DHA: health benefits throughout life. Advances in nutrition, 3(1), 1-7. [Link]
Tocher, D. R., Betancor, M. B., Sprague, M., Olsen, R. E., & Napier, J. A. (2019). Omega-3 long-chain polyunsaturated fatty acids, EPA and DHA: bridging the gap between supply and demand. Nutrients, 11(1), 89. [Link]